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Institutionalizing Techniques for Building Hillside and Levee Ponds for
Water Supply and Aquacultural Development in Latin America
Adoption/Diffusion Research 1 (10ADR1)/Study/El Salvador, Honduras, and Nicaragua
Escuela Agrícola Panamericana, Zamorano, Honduras
Daniel E. Meyer
Joseph J. Molnar
University of Georgia
E. William Tollner
George Pilz, Escuela Agrícola Panamericana, Zamorano, Honduras
The overall goal of this study is to collect and develop information required to institutionalize pond design in Honduras and Latin. This study is coordinated with the training activity outlined in other Honduras Project investigations.
Specific study objectives are to:
2) Develop strategies for designing and managing sustainable levee ponds for aquacultural production that reflects local conditions based on local water supply and soil suitability for pond development.
The hillsides of Latin America cover about 1 million km2 and provide livelihood for some 20 million people, among whom roughly half are classified as "poor" and live in marginalized, rural communities (Knapp et al., 1997). Principal Latin American countries (followed by % area in steep-slope agriculture) are: Honduras and Nicaragua (80%), Costa Rica (70%), and El Salvador and Guatemala (75%) (CIAT, 1996). Typically, the hilly landscape is very heterogeneous and made up of small plots. About half of the hillsides ecosystem in Latin America is progressively deteriorating due to the combined effects of deforestation, overgrazing, destructive tillage tech- niques, improper water management and unfavorable socioeconomic conditions (Whiteford and Ferguson, 1991; Knapp et al., 1997). This has serious implications for agroecological sustainability.
Together with other watershed management initiatives (e.g., soil conservation measures, agroforestry), pond aquaculture can play an important role in stabilizing these ecosystems (Scherr and Yadav, 1997) as testified by Asian experiences (e.g., Nepal, the Philippines). Fishponds also serve multiple roles including water conservation, income generation and food production. However, hillside ponds are rare in Latin America apparently because of high costs associated with mechanized earth moving and/or high labor needs for hand construction, and lack of knowledge of alternate designs suited to local conditions. Further, research by both Zamorano (Lee, 1997) and CIAT (1997) suggests that poor understanding of biophysical (landscape) and socioeconomic (lifescape) linkages among farmers in hillside watersheds impedes more sustainable use of land/water resources in Honduras, and by extension, to neighboring countries in Latin America.
Previous objectives (Verma et al., 2001) were to 1) elicit farmers and change agents perspectives about the role of aquaculture within hillside watersheds; 2) identify design criteria for hillside ponds in participation with end users; and 3) develop alternative pond designs suited to local conditions. The team achieved excellent progress toward identifying NGO and other change agent groups within Honduras. We intend to continue this process in surrounding countries via the website and on-site visits via scheduled training sessions.
The process of design criteria identification was systematized by developing computer models (Verma et al., 2000). As design criteria were identified, it became apparent that the water supply function should be separated from the aquaculture production function, enabling production pond design and development in regions where springs and other sources provided adequate water. In regions where water supply was to be developed by capturing precipitation runoff, a watershed/hillside pond design model coupled with the aforementioned aquaculture production model will be used in tandem. Six regions had good quality monthly precipitation data. One region had reasonably good precipitation-depth-duration data. Local intelligence is required to estimate how one can extrapolate these data to the six regions. The hillside/watershed catchment model evaluates a monthly water balance and determines a minimum watershed size for a desired pond size, nine out of ten years. The minimum watershed size depends on the watershed steepness and cover. Since the actual watershed size may be larger, principle and emergency spillways are designed to handle the 2-year and 10-year storms, respectively. The levee pond model was constructed to perform a monthly water balance, where evaporation, seepage, direct rainfall and incoming pumpage/springflow rates are the major components. Average volume change is the management output along with time to fill. The levee pond by definition receives no runoff from surrounding lands.
The original approach for objective 3 was to develop designs for each component of a pond and custom design a pond for various representative micro-watershed by integrating appropriate component as is in modular design. It became apparent that this modular design approach was not suitable for the range of variability found in Honduras and the region. Thus, the strategy was shifted from modular design approach to the development and application of computer models by knowledgeable practitioners. The catchment (hillside/watershed) and production (levee) models were developed on the Excel platform due to widespread presence of this platform among NGO groups. The English version of the models is essentially complete, although a detailed users guide is yet to be developed. A Spanish version will be produced. Adding a local soils expert to the team will greatly augment the design effort in that key input parameters will be refined and procedures for assessing the parameters will be institutionalized at the local level.
Aquacultural production need not be the sole purpose of waters contained in the hillside/watershed pond. We need to communicate these results to contractors and engineers involved in water supply development and aquacultural production. Additional local intelligence is needed to refine input parameters related to runoff coefficient estimation, seepage rates associated with various soil types and monthly evaporation rates at various regions within the country.
In this study, tools that have been developed by UGA, Zamorano, CIAT, and the SANREM CRSP (Bellows et al., 1995) will be used in a participatory setting with NGO groups to elicit their perspectives on linkages between pond aquaculture operations and watersheds in two countries surrounding Honduras. This effort will build upon the recent experience in Honduras (Molnar et al., 2001; Verma et al., 2000). We believe that this will lead to an increased understanding (among farmer groups and technical assistance personnel) about how natural resources within watersheds can be utilized in a more sustainable fashion. Additionally, we will use concurrent (implying a participatory process) engineering design principles (Veland, 1992) to identify the needs of fish farmers ("customers") interested in hillside aquaculture, their socioeconomic and environmental constraints, and the level of technologies available to construct ponds. These criteria will then be used to develop alternate designs (which address farmer needs and constraints) that can be used for pond construction following the Honduran strategy presented by Verma et al. (2000).
The timing for water development work in Latin America is excellent given the in-country recovery effort following hurricane Mitch. Considerable data collection efforts relating to soils and runoff estimation are currently underway. Thus the time is right for dovetailing modeling parameter needs with other ongoing efforts. The models provide a platform for comparing and contrasting water runoff and sediment transport from watersheds under various cover conditions.
Quantified Anticipated Benefits
This work will result in a hillside/watershed Excel-based model and an aquacultural production pond model. Seepage rate parameters, curve number parameters, permeation rate and peak runoff parameter data for important fish production regions in Honduras will be determined. Four to five training sessions for NGOs, engineers and contractors, with 25 persons per session, will be completed. Two or three students from Zamorano will be partially reimbursed for senior level tuition expenses. Instrumentation for measuring location (GPS), soil texture, seepage and hydraulic conductivity will remain for continued use at Zamorano.
An improved understanding of biophysical and socioeconomic linkages between aquaculture and the associated watersheds has important implications for sustainable resource management. The work will also help to document perspectives of farmer communities with regard to the role of aquaculture in the agroecosystem(s), which will provide insights into better ways of introducing technology. An indirect benefit is the training (with elements of natural resource planning, social perspectives of resource use, and agricultural-aquacultural interactions) that Zamorano staff will gain. The lack of such interdisciplinary training has been identified as a major weakness of the National Agricultural Research System (NARS) in Honduras (Contreras, 1992).
Location of Work: The field work for this study will occur in a representative hillside micro-watershed in the Comayagua department of Honduras. A major portion of the work will, however, will occur at Zamorano and at UGA campuses where additional facilities and expertise is available.
Methods: The proposed plan includes the following sequence of tasks:
We anticipate expanding the activities of this project to surrounding countries in Latin America by including travels to identify potential NGOs with interest in aquacultural production. Focus group sessions and training sessions (see the work plan for 10ATR1) are scheduled to be completed in Nicaragua and El Salvador, in addition to Honduras. Model delivery and training sessions are likewise scheduled in these countries. This work will be coordinated with efforts of the RDS website development work.
Work will commence by September 2001. Initial tasks (identification of watersheds, strengthening of institutional linkages, and refinement of design parameters) are scheduled for completion by December 2001. Soil sampling expeditions are scheduled for completion for completion by December 2001. The Focus group tasks (Honduras, Nicaragua, El Salvador) are scheduled for completion by March 2002. Final training and model delivery (Honduras, Nicaragua, El Salvador) is scheduled for completion by March 2003.
Two reports, spanning the two years of this study, are scheduled for submission to the PD/A CRSP by 30 April 2002 and 30 April 2003. Final report to be submitted by 30 April 2003.
Bellows, B.C., G. Buenavista, and M. Ticsay-Rusco (Editors), 1995. Participatory Landscape/Lifescape Appraisal, Volume 1. SANREM CRSP Research Report 2-95. Sustainable Agricultural and Natural Resource Management CRSP, University of Georgia, 171 pp.
CIAT, 1996. CIAT Hillsides Program. Annual report 1994-1995. International Center for Tropical Agriculture, Cali, Colombia.
CIAT, 1997. Community-led management of watershed resources in hillside agro-ecosystems of Latin America. Annual highlights for project PE-3. October 1997. International Center for Tropical Agriculture, Cali, Colombia.
Contreras, M., 1992. The organization of a small-country agricultural research system with broad research demands: Institutional diversity in Honduras. ISNAR Small-countries Study Paper No. 4. The Hague: International Service for National Agricultural Research, 46 pp.
Knapp, E.B., J.A. Ashby, H.M. Ravnborg, and W.C. Bell, 1997. A landscape that unites: community-led management of Andean watershed resources. Presentation at the 52nd Annual Conference of the International Soil Water Conservation Society, Toronto, Ontario, Canada. 2226 July, 1997.
Lee, M.D., 1997. Communicating natural resource sustainability issues using an interactive group game. Proceedings of the AWRA/UCOWR Symposium on Water Resources Education, Training and Practice, 29 June3 July 1997. Keystone, Colorado.
Molnar, J., T. Popma, F. Arias, B. Verma, and W. Tollner, 2001. Aquacultural development in Honduras: a multi-disciplinary approach. Published Abstract. Annual Meeting of the American Association for the Advancement of Science, San Francisco, California.
Scherr, S.S. and S. Yadav, 1997. Land Degradation in the Developing World: Issues and Policy Options for 2020. 2020 Vision Brief No. 44, IFPRI, Washington, D.C.
Veland, C., 1992. Engineering by design.
Verma, B., E.W. Tollner, T. Popma, J.J. Molnar, and D. Meyer, 2000. Concurrent design of hillside ponds for Tilapia production. 5th International Symposium on Tilapia in Aquaculture, 37 Sept., Rio de Janeiro, Brazil.
Verma, B., Tollner, E.W., T. Popma, D. Meyer, and J.J. Molnar, 2001. Linkage of aquaculture within watersheds and concurrent design of hillside ponds. In: D. Clair, K. McElwee, A. Gupta, D. Burke, and H. Egna (Editors), Eighteenth Annual Administrative Report. Pond Dynamics/Aquaculture CRSP, Oregon State University, Corvallis, Oregon, pp. 4849.
Whiteford, S. and A.E. Ferguson, 1991. Harvest of Want: Hunger and Food Security in Central America and Mexico. Westview Press, Boulder, Colorado, 264 pp.
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